Timer switch having movable piston and mercury contacts



H. E. FREY Nov. 3, 1964 TIMER SWITCH HAVING MOVABLE PISTON AND MERCURY CONTACTS Filed Dec. 7, 1960 INVENTOR. HAROLD E. FREY BY fwd/$241M! mfl 4 w Afforncys Fig. 3.

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United States Patent 3,155,785 TIMER SWITCH HAVENG MUVABLL'J PESTGN AND MERCURY @(BNTACTS Harold E. Frey, 3 Tilden Road, Brownshurg, 1nd. Filed Dec. '7, 1960, Ser. No. 74,340 6 Claims. (Cl. 200-33) The present invention relates to a timer switch which finds an important utility as a control for a washing machine or the like.

Presently available timer switches for washing machines and the like are relatively complicated mechanisms incorporating a large number of working parts. Such switches involve a large original or initial cost and also frequent and expensive repairs. Therefore, a primary object of the present invention is to provide a timer switch which is relatively inexpensive and simple to construct and re am it further object of the present invention is to provide an improved timer switch.

Still a further object of the present invention is to provide a timer switch which can be easily converted for use in diiierent circuits such as on different models of washing machines.

Another object of the present invention is to provide a timer switch which will not need repairs as often as presently available timer switches.

Related objects and advantages will become apparent as the description proceeds.

One embodiment of the present invention comprises a timer switch including a body having a vertically extending chamber within which is movably mounted a piston. The body has a passage leading therethrough from one end of the chamber to the other end thereof and has electrical contacts mounted in said body in such a manner as to form a part of the wall of the chamber. Mercury is received in the chamber upon the piston so as to urge the piston downwardly through the chamber. Non-conductive liquid is received within the chamber and in the passage and acts to resist downward movement of the piston by moving through said chamber and passage whereby said piston moves at a predetermined rate and said mercury electrically connects said contacts as the piston moves thereby through said chamber.

The full nature of the invention will be understood from the accompanying drawings and the following descrip tion and claims.

FIG. 1 is a vertical section of a timer switch embodying the present invention taken along the line 1-1 of FIG. 2 in the direction of the arrows.

FIG. 2 is a vertical section of the timer switch taken along the line 2-2 of FIG. 1 in the direction of the arrows.

FIG. 3 is a detail view of the inside surface of a terminal board forming a part of the timer switch.

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawing and specific language will be used to describe the same. It will never-.

theless be understood that no limitation of the scope of the invention is thereby intended, such alternations and further modification in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now more particularly to the drawings, there is illustrated a timer switch including a body made up of a base 11 and a cover plate or terminal board 12. The base 11 has a generally rectangular shape and has formed therein a generally rectangular chamber 15 which receives a piston arrangement 16 for reciprocation therein. The base also has formed therein a passage 17 which branches into three passages 18, 19 and 20. The passages 18-2ll lead from the lower end of the chamber 15 into the passage 17 which in turn leads into the upper end of the chamber 15.

Flow through the passage 19 is controlled by a ball check valve 21 including a ball 22 which seats in the entrance 25 to the passage 19. It can be appreciated that the ball 22 will permit flow from tht pasage 19 into the chamber 15 but will prevent flow in an opposite direction. Flow through passages 18 and 21 is controlled by ball check valves 26 and 27, respectively, which are received in enlarged portions 30 and 31 of the passages 18 and 2d. The valves 26 and 27 operate similarly to the check valve 21 but are each additionally provided with solenoids 32, one of which is not shown. Each passage 18 and 20 is provided with an insert 33 and 34 which have orifices of different sizes therethrough to correspond, for example to the requirements of different appliance manufacturers. By way of example, the orifice of insert 33 could be smaller than that of insert 34. Thus, solenoid 32 of valve 26 may be operated to permit a relatively small flow from the lower end of the chamber 15 into the passage 17. An intermediate amount of flow can be achieved by opening of the valve 27 by its solenoid 32 and a relatively large amount of flow can be achieved by opening both valves 26 and 27.

The piston arrangement 16 includes a piston element 35 which has secured thereto a shaft 36 having an operating handle 37 fixed to the extending end thereof. Re ceived within the concave portion 41 of the piston element is a quantity of mercury 41 and also a pair of magnets 42 which act to maintain the mercury adjacent the piston element 35.

The cover or terminal board 12 is secured to the base 11 by means of suitable screws 45 and, along with the base 11, is formed of a non-conductive material. The board 12 has on its inner face 46 a protruding portion 47 within which is mounted, flush with the surface of the protruding portion, a number of contacts or terminalss 5053, each of which is electrically connected to a respective lead wire sea-53A. In the particular embodiment illustrated, the board 12 is formed with the protruding portion in order that the depth of the chamber 15, that is the distance from the cover to the deepest portion of the chamher, is a standardized dimension only slightly greater than the depth of the piston element 35. A generally rectangular gasket 55 is received between the cover 12 and the base 11 and acts to seal the chamber 15 and to prevent leakage from the chamber and passages which are filled with a non-conductive liquid such as oil.

In order to operate the timer switch, the handle 37 is moved upwardly causing the piston arrangement 16 to move upwardly in the chamber 15 and causing the lower portion of the chamber to be filled with oil which passes from the upper portion of the chamber through the passages 17-26 and through the ball check vales 21, 26 and 27. Depending upon the speed of downward movement desired for the piston arrangement, either or both the valves 26 or 27 are opened by means of the solenoids 32 and the piston arrangement moves downwardly at the desired rate. The terminal or contact 5a may be, for example, a common terminal which is connected in turn to the terminal 53, the terminal 52 and the terminal 51 by means of the mercury 41 which extends a sutficient distance above the upper edges of the piston element 35 in order to electnically connect the terminals to which it is adjacent. It should be noted that in the preferred embodiment of the invention, the piston element 35 is formed of a non-conductive material.

It can be appreciated that the terminals or contacts 5053 can have any desired length whereby the period or duration of connection of a respective terminal with the mercury 41 can be any desired length. it should also be mentioned that the various terminals may overlap. For example, the terminal 53 may be connected to the terminal 50 during the connection of the terminal 52 thereto. The speed of the piston arrangement 16 and the corresponding length of the cycle will be determined by the amount of constriction or the size of the orifices in the inserts 33 and 34. As has been suggested above, the device requires no springs or other power providing means because gravity is used to move the piston arrangement downwardly. Of course, the great weight of the mercury received within and above the piston element 35 aids in moving the piston downwardly.

From the above description, it can be appreciated that the present invention provides an improved timer switch finding an important utility as a control for a washing machine. It can also be appreciated that the present invention provides a timer switch which is relatively inexpensive and simple to construct and repair. It should also be mentioned that the terminal board 12 can easily be replaced by a terminal board having a difierent terminal arrangement thereon whereby the timer switch may be converted for use in different circuits such as on dilferent models of washing machines.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

The invention claimed is:

1. A timer switch comprising a body having a vertically extending chamber therein, a piston movable in said chamber, said body having a passage leading therethrough from one end of said chamber to the other, electrical contacts mounted in said body and forming part of the wall of said chamber, mercury received in said chamber on said piston ending to move it downwardly through said chamber, and a non-conductive liquid filling said chamber and passage, said passage being constricted a predetermined amount whereby said piston moves at a predetermined rate by forcing said nonconductive liquid through said passage and said mercury electrically connects said contacts.

2. A timer switch comprising means defining a cham her, a piston arrangement movable in said chamber and guided by the sides of said chamber, said piston arrangement being electrically conductive, electrical contacts monuted'in the sides of said chamber for electrical connection by said electrically conductive piston arrangement as said piston arrangement moves by and engages said contacts, and a non-conductive liquid received in said chamber and resisting movement of said piston arrangement through said chamber, said electrical contacts extending different distances in the direction of movement of said piston arrangement and being at different overlapping locations along the path of said piston arrangement whereby said contacts are electrically connected at predetermined times in predetermined sequence.

3. A timer switch comprising a body including a base having a vertically extending chamber therein, a piston movable in said chamber, a handle secured to said piston for the raising thereof, said base having a passage leading therethrough from one end of said chamber to the other, a cover for said base secured thereto and closing said chamber, electrical contacts mounted in said cover and forming part of the wall of said chamber, mercury received in said chamber on said piston tending to move it downwardly through said chamber, a non-conductive liquid filling said chamber and passage, said passage being constructed a predetermined amount whereby said piston moves at a predetermined rate by forcing said non-conductive liquid through said passage and said mercury electrically connects said contacts.

4. A timer switch comprising a body having a vertically extending chamber therein, a piston movable in said chamber, said body having a passage leading therethrough from one end of said chamber to the other, electrical contacts mounted in said body and forming part of the wall of said chamber, mercury received in said chamber on said piston tending to move it downwardly through said chamber, a non-conductive liquid filling said chamber and passage, said passage being constricted a predetermined amount whereby said piston moves at a predetermined rate by forcing said non-conductive liquid through said passage and said mercury electrically connects said contacts, a check valve controlling ilow through said passage arranged to permit flow through said passage into the lower end of said chamber but to prevent flow through said passage out of the lower end or said chamber, and means for opening said check valve to permit downward movement of saidpiston at a desired speed.

5. The timer switch of claim 4 wherein said electrical contacts extend different vertical distances and are at different vertically-overlapping locations whereby said mercury electrically connects said contacts at predetermined times in predetermined sequence.

6. A timer switch comprising a body having a chamber therein, a piston arrangement movable in said chamher, said body having a passage leading therethrough from one end of said chamber to the other, a removable cover plate forming one wall of said chamber, electrical contacts mounted on said cover plate and facing into said chamber, and a non-conductive liquid lilting said chamber and passage, said passage being constricted a predetermined amount whereby said piston moves at a predetermined rate by forcing said non-conductive liquid through said passage, said piston arrangement having an electrically conductive portion arranged to electrically connect said contacts as said piston moves thereby through said chamber, said electrical contacts extending different distances in the direction of movement of said piston arrangement and being at dilterent overlapping locations along the path of said piston arrangement whereby said contacts are electrically connected at predetermined times in predetermined sequence.

References Cited in the file of this patent UNITED STATES PATENTS 1,983,150 Sigrnan Dec. 4, 1934 2,407,571 Miller Sept. 10, 1946 2,606,256 Sissenwine et al. Aug. 5, 1952 2,614,239 Smith et al Oct. 14, 1952 2,794,868 McMorran et al June 4, 1957 3,045,076 Gaylord July 17, 1962 FOREIGN PATENTS 8,5G4 Great Britain July 1, 191.5 133,122 Great Britain Sept. 19, 1919 689,132 France May 20, 1930 577,794 Great Britain May 31, 1946 

2. A TIMER SWITCH COMPRISING MEANS DEFINING A CHAMBER, A PISTON ARRANGEMENT MOVABLE IN SAID CHAMBER AND GUIDED BY THE SIDES OF SAID CHAMBER, SAID PISTON ARRANGEMENT BEING ELECTRICALLY CONDUCTIVE, ELECTRICAL CONTACTS MONUTED IN THE SIDES OF SAID CHAMBER FOR ELECTRICAL CONNECTION BY SAID ELECTRICALLY CONDUCTIVE PISTON ARRANGEMENT AS SAID PISTON ARRANGEMENT MOVES BY AND ENGAGES SAID CONTACTS, AND A NON-CONDUCTIVE LIQUID RECEIVED IN SAID CHAMBER AND RESISTING MOVEMENT OF SAID PISTON ARRANGEMENT THROUGH SAID CHAMBER, SAID ELECTRICAL CONTACTS EXTENDING DIFFERENT DISTANCES IN THE DIRECTION OF MOVEMENT OF SAID PISTON ARRANGEMENT AND BEING AT DIFFERENT OVERLAPPING LOCATIONS ALONG THE PATH OF SAID PISTON ARRANGEMENT WHEREBY SAID CONTACTS ARE ELECTRICALLY CONNECTED AT PREDETERMINED TIMES IN PREDETERMINED SEQUENCE. 